When To Put Baby Fish In Regular Tank?

[DanielleC]

I have a rainbow platy and swordtail that had babies. There's only one surviving baby, and he is at least 6 months old (I'm not sure exactly how old). I've been keeping him in a small baby tank. The other tank is a 10 gallon tank with 3 tetras and the rainbow platy (the baby's father). I want to know when it will be okay to release the baby. I'm worried because he is still so small, and might be bullied, or even eaten, by the other fish.

 

[fluttermoth]

There's going to be no easy way to say this, so I'll apologise in advance...

I'm afraid your baby fish is probably stunted. This happens to fish when they're are kept in tanks that are too small or that don't get enough water changes. The scientific reasons for this aren't well understood as yet, but it is a very real phenomena. He should have been adult sized by now.

There's not an awful lot you can do, although getting him in a bigger tank and giving him a lot more water changes (I do 50% every other day when I'm growing on fry) might help him grow a bit more.

How big is the tank he's in at the moment, and how often and how big are your water changes?

 

[DanielleC]

There's going to be no easy way to say this, so I'll apologise in advance...

I'm afraid your baby fish is probably stunted. This happens to fish when they're are kept in tanks that are too small or that don't get enough water changes. The scientific reasons for this aren't well understood as yet, but it is a very real phenomena. He should have been adult sized by now.

There's not an awful lot you can do, although getting him in a bigger tank and giving him a lot more water changes (I do 50% every other day when I'm growing on fry) might help him grow a bit more.

How big is the tank he's in at the moment, and how often and how big are your water changes?

He's in a mesh tank that rests in the bigger tank. So there's always different water being filtered through it. And it gets changed along with the bigger tank, about every week or so. Unfortunately, it's not a very big tank. I was unable to find a larger one. 

 

[fluttermoth]

Those mesh things really don't let enough water flow through to prevent stunting

All you can do is up your water changes and see if he starts growing; some do, so you might be lucky.

How big are your current weekly water changes?

 

[DanielleC]

When I change the water weekly, I change all of the water. 
 
If I let him out now, does he risk being eaten by the other fish? And does stunting cause a shorter life span, or will he still have a regular life span?

 

[fluttermoth]

If he's small enough to fit in the other fish's mouth's, he is at risk, yes

Stunting usually does significantly shorten a fish's lifespan, and makes them more likely to catch other diseases as well.

 

[DanielleC]

I feel really bad now. I had no idea keeping him in the small tank did these things. Actually, I thought I was doing him good by keeping him away from the other fish. 
I want to be prepared for the next time my fish have babies and not make the same mistake again. So how long should I leave them in the small tank before stunting happens? 

 

[fluttermoth]

If you change all the water in the breeder box at least once and preferably twice a day, the new fry should grow better, but it really is better to leave them in the main tank. If you have enough hiding places some fry will escape being eaten.

How do you clean the main tank, if you're changing all the water; do you take the fish out and clean the whole tank? How do you clean your filters; in old tank water or under the tap?